Unfortunately your present symptoms usually mean that your cylinder head is warped/headgasket related problem. I'd assume that the engine was previously driven without enough coolant thus overheated? Seen this happen many times.

It can be properly diagnosed by using a device called a "block tester" that has a liquid that changes color when CO is detected in the cooling system. If so, it's not a cheap fix as the cyl head must be removed and sent to a machine shop to be straightened, machined.